D-Allopyranoside, methyl

Our initial studies were directed towards the synthesis and characterization of phenylboronate esters derived from methyl 6-deoxy-/ -D-allopyranoside, methyl a-L-rhamnopyranoside, methyl -L-fucopyranoside, and methyl 6-deoxy-/ -D-glucopyranoside. Previous work (14) in this laboratory indicated that the reaction of triphenylboroxole and methyl... 

Me glycoside Methyl 6-deoxy-2,3-di-0-methyl-p-D-allopyranoside. Methyl P-d-mycinoside C9H18O5 206.238... 

Two polymorphs of a,a-trehalose octacetate monohydrate, 4,4 -dideoxy-a,a- ty/o-trehalose, methyl 2,3,4,6,2, 4, 6 -hepta-C -acetyl-a-laminaribinoside, 2 3,3 -dideoxy-a,a-flrflbjno-trehalosc. 3 Methyl 2,3-0-isopropylidene-5-0-tosyl-P-D-ribofuranoside 2, the 7-carbon glycoside 3 (see Chapter 17), C-glycosidic furanoside 4 (see Chapter 14) the oxazoline derivative 5 and methyl 1,6-di-0-(4-bromobenzoyl)-3,4-di-0-(4-methoxycinnamoyl)-P-D-fructofuranoside. Di-(3-deoxy-D-g/yccro-pcntulose)-l,2 2,r-dianhydridc, methyl 4,6-benzylidene-a-D-allopyranoside, methyl-2,3,4-tri-0-acctyl-a-L-rhamnopyranoside, l 2-(indol-3-yl)ethyl 2,3,4-tri-O-acetyl-a-L-... 

Methyl 3-D-Mannopyranoside Methyl a-D-Allopyranoside Methyl P-D-Allopyranoside... 

In a second approach (see Figure 3) the alloside derivative 11 was converted, by mild acid hydrolysis, into methyl 2-O-toluene-p-sulfonyl a-D-allopyranoside (18). Acid catalyzed acetonation of compound 18... 

The Action of Alkali on Methyl 2 3-Anhydro-a-D-allopyranoside and l 5-Anhydro-2-deoxy-3-0-toluene-p-sulphonyl-D-arabino-hexitol," A. B. Foster, M. Stacey, and S. V. Vardheim, Acta Chem. Scand., 12(1958) 1819-1824. 

Methyl 3-azido-4-0-benzoyl-6-bromo-2,3,6-trideoxy-2-fluoro-a-D-allopyranoside... 

C17H23Br09 Methyl 2,3-anhydro-6-bromo-6-deoxy-4-0-(4,6-di-0-ace-tyl-2,3-dideoxy-a-D-erythro-hex-2-enopyranosyl)-a-D-allopyranoside (MBEHAP)98... 

Reactivity at 0-3, in addition to that at 0-4 and 0-6, was observed with methyl )3-D-galactopyranoside, which, when treated with sulfuryl chloride, yielded methyl 3,4,6-trichloro-3,4,6-trideoxy-/J-D-allopyranoside 2-(chlorosulfate) in 56% yield.352 In contrast, under similar conditions, methyl a-D-galactopyranoside gave352 methyl 4,6-dichloro-4,6-dideoxy-a-D-glucopyranoside 2,3-di(chlorosulfate). Further examples of the dependence of the reactivity on the configuration of C-l are the conversion of methyl 4,6-0-benzylidene-/3-D-glucopyranoside into methyl 4,6-0-benzylidene-3-chloro-3-deoxy-/3-i>allopyranoside by sulfuryl chloride,352 and of methyl 4,6-0-benzylidene-a-D-glucopyranoside, under similar conditions, into the 2,3-di(chlorosulfate).355... 

An important step in the synthesis of paratose (3,6-dideoxy-n-rtfoo-hexose) involved the conversion of methyl 3-chloro-3-deoxy-/8-D-allopyranoside into methyl 3,6-dichloro-3,6-dideoxy-/8-D-allo-pyranoside in 33% yield.359... 

On treatment with 30 equivalents of methanesulfonyl chloride in N,N-dimethylformamide for 8 days at 65°, methyl /3-maltoside gave a mixture of methyl 3,6-dichloro-4-0-(6-chloro-6-deoxy-a-D-glucopyranosyl)-3,6-dideoxy-/3-D-allopyranoside, isolated in 46%... 

In the aldohexopyranose series, treatment of methyl 2,3-anhydro-4,6-di-O-methyl-a-D-allopyranoside (34), or of the corresponding 4,6-diacetate (39), with hydrogen tetrafluoroborate in hydrogen fluoride at 70° afforded121 the corresponding derivatives of 2-deoxy-2-fluoro-D-al-tropyranosyl fluoride (35 and 40) and 3-deoxy-3-fluoro-D-glucopyrano-syl fluoride (36 and 41). Compounds 35 and 36 were hydrolyzed, and... 

Y. Ali and A. C. Richardson, The reduction of azides with sodium borohydride. A convenient synthesis of methyl 2-acetamido-2-deoxy4,6-0-benzylidene-a-D-allopyranoside, Carbohydr. Res., 5 (1967) 441 448. 

Y. Ali, A. C. Richardson, C. F. Gibbs, and L. Hough, Some further ring-opening reactions of methyl 4,6-0-benzylidene-2,3-dideoxy-2,3-epimino-a-D-allopyranoside and its derivatives, Carbohydr. Res., 1 (1968) 255-271. 

A novel method of opening of oxiranes involves the use of (chlo-romethylene)dimethyliminium chloride (39) [see Section II,2c p. 250], monochlorodeoxy or dichlorodideoxy derivatives are obtained, depending upon the reaction conditions employed.83 Thus, methyl 2,3-anhydro-4,6-0-benzylidene-a-D-allopyranoside (110) reacts with 39 in 1,1,2,2-tetrachloroethane at room temperature to give, upon hydrolysis of the primary adduct 111 with an aqueous solution of sodium hydrogen carbonate, methyl 4,6-0-benzylidene-2-chloro-2-deoxy-3-0-formyl-a-D-altropyranoside (112). If a solution of 39 and 110 in 1,1,2,2-tetrachloroethane is heated at reflux temperature, methyl 3,4-0-benzylidene-2,6-dichloro-2,6-dideoxy-o -D-altropyrano-side (113) is obtained in high yield the n.m.r. spectrum of 113, like that of 47 (see Section II, 2c p. 250), showed the presence of two diastereoisomers which differed in the configuration of the benzyl-idene-acetal carbon atom. 

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